Apparatus for controlling the movement of vehicles on railroads



May 31, 1932. g: SPRAGUE APPARATUS FOR CONTROLLING MQNEM N? 9 YEE RAILROADS Original Filfid April 11?,- 1 2E 27 Fly. 30'

A T TORNE Y5.

Patented May 31, 1932 .Tesi

FRANK a. srimenn, on N Yonn, N, Y, ASSIG-NOB "r0 SPBA UE AFE Y Q-ON ROL &

SIGNAL eonronn'rion, on new onn, n. Y., .A oonrosnrionor v noxnrn. I

nrrnne'rns non oontrnonnineanni iovn vrnn'ror vnn onnsion' RAI nonns Original application filed April 12, 1927, Serial No. 183,193. Divided and this application fileglfl'uly 6,

1929. Serial This application is filed as a division of my prior application, Ser. No. 183,193 of April 12, 1927, for apparatus for controlling movement of vehicles on railroads, and the subject hereof forms part of the apparatus disclosed in the aforesaid application.

My invention relates to an improvement in automatic train control systems,and particularly to the features known as forestall ing and resetting, the former being-an operation by which the engineer may, by the performance 01"- a suitable manual act, prevent the coming on of an automatic brake application, and the latter an operation by which the brake controlling apparatus may be i restored .to normal condition, after which the brakes (if applied) may be released and-free running conditions established.

In much of present practice the-forestalling and resetting operations are eiiected by mechanisms differently placed, the forestall ing being done in the cab, and the resetting through a switch or other device situated at such inconvenient point as will require the train to be stopped before it can be used, so as to prevent release of the brakes, applied in response to a track initiatedimpuls'e, before the train has come to rest, although sometimes this reset switch is made inconvenient but possibly accessible when the train is moving at slow speeds.

To place some restriction upon the act-of forest-alling, which unless limited by the condition that a train must be actually braked or has had its speed reduced to some predetermined rate althoughipresent practice and ruies actually permit forestalli'ng at any 7 speed and without any pre-application ofthe brakesit has been proposed to limit the time period in which the engineer may fore stall an automaticlorakeapplication whenreceiving atrack impulse. This is done in certain electrically controlled systems by connecting a forestalling switch and circuits so that after manual operationiofthe switch by the engineer the forestalling circuit will-be closed, and the essential circuit will'be maintained for only a limited time, the movement of the switch handle initiating a'metive force which after a short interval .will openthees- No. 375,409. I

sential circuit, just as the-pilot circuits are made and opened in my, Letters Patent No. 660,065 on the multipleunit; system'or" train control, p -f a YVithjthis arrangement, the engineer, on approaching a stop indication point Within distanceless thanhe'will cover in a predeterminedtime, which may be anything from a hundred to a thousand feet or more, accord.- ing to the speed of a train, moves his switch to the forestallijng position, closes the forestalling circuit and initiates the motive force, which will open the essential circuit auto.-

omatically in a predetermined time say 15 seconds. After pass ngfthe stop indication point, if he returns-the switch to the normal position within thetime period there will be no automatic braking, although some part of the equipment may be responsive. But if the switch is held in the forestallin g position for longer than the time period thebrakes will come on.

Thus there are three conditions in which the automatic brake application may take place as a resultof passing a'stop indication point. .First, if the engineer does nothing;

second, it he forestalls too soon; and, finally,

if he holds on too long. Any of these conditions may possibly act adversely as regards train movements. v i

With the automatic brake application in effect, the amount of braking is made-such as to bring the train to a stop, after Whieh'the engineer or fireman mustgetidownirom the cab, or climb out to ,aposition diifioult of access when the loeomotiveis moving, to reset the brake initiating apparatusso that the engineer may release the brakes manually.

-- The main object ofthus separating'the forestalling and resetting actions, and providing for a time limit is to inducejsome measure of alertness on. the part of theengineer, under possible p enalty, .and to insure that once the brakes.v haveactuallylcome on automatically the train shall, be stopped be fore the engineer ;c-anrelease themp :1

There are serious objections to bothaprac- V tices, and specifically to the lack of restric- 'tion of the use ofia'forestalling'device,-as well as to the necessity. tor. gettingxout of thelcab to enable the brakes to be released. This latter act cannot be performed at times without serious danger, as in tunnels, snow-sheds and on trestles, or in proximity to passing trains and under conditions of poor Visibility.

I desire, therefore, to provide definite limitations upon the act of forestalling, as well as upon the act of resetting, while the timing"mechanism for opening the forestalling circuit may be omitted'entirely. I plan, also, to combine in a single mechanismoperated in the cabboth the fore stalling and resetting operations, and for compelling, under possible penalty, acknowledgment of the receipt of a brake initiating impulse from the track; This mechanism may conveniently be referred to as an acknowledging device. 7

My invention will conduce to, safety and convenience, and eliminate delays, while making it possible to impose upon the engineer such precautionary conditions as are assential to safe operationfan'd the maintenance of the fundamentals of automatic train control systems.

The accompanying drawings and specification illustrate my invention as applied to a system of automatic train control'wh-ich cooperates with the usu'al'type of air brake equipment in whole or in part. It is of-course applicable not only to vehicles propelled by steam but to vehicles otherwise propelled. It should be noted that; the mechanic, electrio and pneumatic devices shownin these drawings servemerely to illustrate the natureof the invention, and thus do not limit of the rotatable contactor mechanism of the acknowledging device F2 of Fig. 1.- v Figs. 3a, 3b and 3c are schematic side views of the rotatable contactors 118 and 119 of Fig. 3; Fig. 3a showing relative position of r the rotatable and stationary contacts in normal running position, Fig. 3?) being an interretained in its operated position.

Relay R representsthe governing element of the circuits. This relay is normally energized, its maintaining circuit being the fol-' lowing: From the positive side of the battery H, contactorA, contacts 6,armature 2," and coil of relay R, back to the negative battery. As the' maintaining circuit of relay R includes its own armature 2 it is a fstick be controlled by track elements.

mined maximum valuei I As IDBIltlOIlGCl prev ously, when the stick relay which, when once de-energized, cannot be re-energized by way of its normal maintaining circuit.

The contactor A represents an element for changing the electrical condition of the governing element of the circuits, which element is herein illustrated as a stick relay. The contactor A is for convenience illustrated as biased bya spring 18 and is intended to In the specific illustration it is normally held by its spring against its cooperating contact so as to close the maintaining circuit of relay R.

as to open the maintaining circuit of relay R r at contact 7 The word active in this connection. refers to the condition of the track element which is intended to initiate automatic brak ing and does not refer to the inherent condition of the track element itself. The term track element is likewise employed in its broadest sense irrespective of the type of system, whether continuous or intermittent, to which my invention is applied.

For illustrative purposes the intermittent inductive type of system may be referred to, such, for example, as is shown in my British Patent 1 No. 18,213 of 1915, and British Patent No. 149,922, or.,my U. S. Patent No. 1,669,165, of May 8, 1928. In each of these the track element when active may result circuit from normal to operative condition.

More precisely in the specific illustration herein the contactor A may be considered as opened by magneticattraction from an active trackelement.

The stick relay R normally maintains its armature 1 againsta contact 4: in the normally closed circuit of an electro-pneumatic vent valve V. r

The vent valve V represents the connecting member between the electric and pneumatic parts of the vehicle-carried equipment, de-i energization of which valve initiates an automatic brake application. Various pneumatic equipment may be used in connection with my invention-for instance, the one described in my previously referred to application, Ser.

No. 183,193 of April 12,1927.

contact 133-to the coil'20 of the vent valve and contact 4 and armature 10f relay R,back

vided, as more fully'explainedlater on, the

speedof the train does not exceed a predeterrelay Rv is -de-energi zed, as happens when passing over an active application track element, it cannot be re-energized by way of its normal maintaining circuit, even if such track element is passed and contactor A has as sumed its normal position; such re-ener ization can only take place by way of re-en'ergizing circuit. These circuits, and the .devices associated therewith, will now be described. The devices just referred to are an acknowledging device F2, :1 speed-governor M1, and a sylphon-operated contactor B.

The acknowledging device F2 is illustrated in Figs. 3, 3a, 3Z1 and 3c, the normal position being shown in Figs. 3 and 3a, an intermediate position in Fig; 3b and the final position prior to automatic return of the device to normal in Fig. 30. Two cylindrical contactors 119 and 118 are mounted on a shaft 109. The contactor 119 is fixed to the shaft. The contactor 118 is not rigidly fixed to the shaft but is connected therewith by a spiral spring 117 located within an annular space in the contactor. This spring tends to move the contactor towards its operative position, but normally the contactor is held in inoperative position by engagement of a rod 121 aiiixed to the contactor 118 and projecting laterally therefrom with one end in an annular slot 122 formed in the contactr 119. A handle 105 is provided on the shaft 109, sothat, when 105 is manually operated the contactor 119 rotates away from the rod 121 and releases the contactor 118 for rotation under the influence of its spiral spring 117. The rotation of the contactor 118 is governed by a clock-work mechanism 120, schematically indicated in Fig. 3, so thatit proceeds evenly and at a lower rate than the normal manual rotation of the contactor 119. The surface of contactors 118 and 119 is of insulating material except for insulated strip contacts g2 and g1 respectively. These strip contacts y 2 and y l are so positioned in respect to the stationary contacts 12,13, 1 10 and 150 that electric connection between contacts 12 and 13 and between contacts 140 and 150 respectively is normally broken.

When the handle 105 is movedto its operated position the strip contact 3 1 bridges contacts 140 and 150. At the same time contactor 118 being released starts to rotate. Shortly after the commencement of this rotat-ion the strip contact of y2 bridges contacts 12 and 13 as shown in Fig. 3?). However, after a certain time lapse the strip contact 3 2 leaves contact 13 and the breaking of the connection between contacts 12 and 13 is again efiected, It is thus only in an intermediate position of contactor 118 that the series bridging of contacts 12, 13, 140 and 150 is broug -t about. The l ngthoi time that this continues is governed by the clock- I work 120 and is at the optionof the road adopting this system. It should be noted that contacts 12 and 13, and 140 and 150'are both normally open and that on completion of rotation of contactor 118 contacts 12 and: 13 are open; further that contacts 140 and 150 are only made on complete manual m ove- Inent ofthe handle 105. This arrangement nullifies the cited; of operating the acknowledging device in the event of failure, for any reason, of the contactor 118 to move and servesas a further. check in preventing intended operation by tying down the handle. Thecentrifugal governor M1 has attached to its movable head a cylindrical circuit breaker 135, the right hand surface of which of insulation 13% and the left handsurface .Lvb of conductive material 133. Three brushes .130, 131 and 132 are provided for cooperacircuit of the coil of the vent valve V;

and brush 132is a'low-speed brush in the forestalling and resetting circuits of the stick relay B. On movement to the left of the circuit breaker 135 by the speed overnor M1 the insulation first reaches the lowspeed. brush 132 and then the high speed brush 131. T he speeds at which the circuits controlled by these brushes are thus broken are matters of adjustment to suitthe re quirements of the road adoptin the system.

Thesylphon-operated contactor B comprises a housing 8 1 in which is mounted a sylplion 83normally under equal air pressures inside and out. The sylphon carries a cap 82 to which is attached astem. 81 which slidably extends through the housing (by means of a substa tially air-tightbushing 85) and supports an insulated disccontact 3. The stem 81is surrounded by an adjustable coil spring 80 which abuts against the bushing and the cap and normally holds the disc contact 3 in its lowermost position. Pneumatic connection ismade with the sylphonoperated contactorby means of pipe 0 which communicates with the chamber 04 inside the sylphon, and pipe 61 which communicates with the chamber 54 outside the sylphonv The operation of the sylphon-operated contactor depends upon a differential of pressure in thechambers c 4 and b4c. f

The differential of pressure in the chainbers c 1 and b lisobtained when an auto-' niatic brake application takes place. lTo achieve this various apparatus canbe used as, for instance, described in my co-pendi'ng application Ser. No. 183,193 of April 12, 1927, and, as governing pressure, .for instance equalizing reservoir or; brakepipe pressure may be used, although as described in my previouslyreferred te -application other governing pressures may be employed.

Normally both chambers :are maintained atequal pressure, but in case an automatic brake application takes place a pressure dif ference between chambers 04: and b l is established with the consequent upward motion of contact 3.

Two lower contacts 10 and 11 are normally connected with each other by the disc contact 3 which connection, however, is. broken when in case of an automatic brake application contact- 3, due to the difierential of pressure in chambers Z)4 and 04, is moved upwardly. l i hen this pressure difference has reached a certain value, depending upon the adjustment of the spring 80 the contact 3 bridges a pair of upper contacts 8 and 9.

The vent valve V is provided with a normally attracted armature 101 which, when the vent valve V is de-energized, bridges a.

pair of contacts 103 and 103.

A warning device which may be audible, visible, or both, and which is represented in the drawing by the audible signal K, is provided. When the relay R is deenergized and drops its armature 1, the circuit of signal K is closed as follows:

From plus battery, through signal K, contact 5 and armature 1 back to negative battery. Y

A time delay is preferably provided be tween the de-energization of the vent valve and the automatic application of the brakes. This time delay may be varied from the fraction of a second to several seconds, depending on the requirements. There are many known ways to provide such a time delay, as, for instance, by the means described in my above referred to application Ser. No. 183,193 of April 12,1927. 7

Under normal conditions the stick relay is energized and its armatures 1 and 2 are attracted; The vent valve is thus energized unless the speedexceeds the maximum speed limit, in which latter case the high-speed brush 131 contacts with the insulated portion 135 of the speed governor and the vent valve is de-energized. This causes an automatic application of the brakes; however, as soon as. the train reduces its speed below the maximum speed limit-the relay R. not having been de-energized-the vent valve is automatically re-energized and the brakes can be released. 7

However, if an active application track element is passed the relay R is ole-energized and can only be re-energized by closing one of its re-energizing circuits which shall be now discussed: I 7

There are two re-energizing circuits for I the stick relay, one being the forestalling circuit and the other the resetting circuit.-

. Both the forestalling and resetting circuits are partly closed uponmanual operation of the acknowledging device; however, comple- 1 tion of the forestalling circuit can onlytake placeprovidedno automatic braking has been initiated, While completion of the resetting plication has taken place.

circuit can only take place if a brake application of a predetermined value] has taken place.

Both the forestallingand resetting circuits go from the plus side of the battery H through the battery brush 130 and low-speed brush 132 of the speed governor v(these two brushes being electrically connected by the contact 133 provided the speed of the train is below the low-speed limit) the contacts 103 and 103,which are bridged only in case the vent valve V is de-energized,to the contacts 1l15 and 1213 of the acknowledging device. At this point the forestalling and reset circuits separate, the forestalling circuit going through contacts 10 and 11 of the sylphonoperated contactor which are normally bridged by contact 3, while the resetting circuit goes through the normally open contacts 8 and 9 of the sylphon-operated contactor. Contacts -8 and 10 are interconnected and from here the two circuits again reunite and go through relay R to the negative side battery H. s

From the foregoing it is apparent that to re-energize the relay B after it has been deenergized the following conditions have to fulfilled: 1. Contact between battery brush 130 and the low-speed brush 132 through contactor 133 must be established, i e., the speed of the train must be below the lowspeed limit. valve V must be dropped so as to bridge contacts 103 and 103. 3. Both pairs of contacts, 12-13 and 145""15 of the acknowledging device F 2 have to be bridged by segments g2 and 2 1, respectively. 4. Either contact pair 1011 or contact pair 89 must be bridged .by disc contact 3.

As contacts 10 and 11 are bridged by the disc contact 3 as long asthe air pressures in chambers 6- 1 and 04l are equal, as previously stated, this implies that no brake ap- Forestalling on the part of the engineer thus will only be effective it aside from the conditions under 1 to 3 being fulfilled, such operation takes place before an automatic brake application has started. 7

7 Contacts 8 and 9 of the sylphon-operated cont-actor are bridged by disc contact 3 if a predetermined amount of brakingdepending on the-adjustment of spring 80has taken place, this being the requirements for resetting aside from the requirements mentioned under 1 to 3.

In operation, upon passage of an active 7 track element, relay B is de-energized, thus causing armature 1 to drop which energizes audible signal K., This warns the engineer Leeanoe pared to heed such warningor is incapacitated to doso; an automatic brake application will then occur. 7

However, if the engineer is alert and wishes to take advantage of the forestalling privilege, upon receipt of the Warning signal he immediately operates forestalling device F2 and as armature 101 bridges contacts 103- 103 due to de-energization of the vent valve) the relay R will be re-energized, provided the speed of the train is below its low-speed limit, as an automatic brake application not having started, contacts 10 and 11 are bridged by disc contact 3. Re-energization of relay R re-establishes the energizing circuit of the vent valve.

VJhile the low-speed contact 132 and the check contacts 103-403 of the vent valve are inserted in the forestalling circuit herein illustrated, provision of such contacts is optional and these contacts may be omitted if so desired.

If the engineer has not forestalled and an automatic brake application has taken place, the engineer, to restore the equipment to normal, has to wait until a fixed brake applicationamount of which is determined by the adjustment of spring 8'Ohas taken place, after which operation of the acknowledging device F2 will re-energize relay R, provided that the speed of the train is below its lowspeed limit. Re-energization of relay R reestablishes the energizing circuit of the vent valve.

While the low-speed contact 132 and vent valve check contacts 103-103 are inserted in the reset circuits here illustrated, these features are optional and can be omitted if so desired.

As previously stated, contact 3 of the sylphon-operated cont-actor is moved upon a differential pressure in chambers ct and 5-4:. Such difference in'pressure will a1- 'ays take place in the case of automatic brake application but, if so desired, arrangement can be made that it also take place in case of a manual brake application, in which case the resetting will depend on the sum of the automatic and manual brake applications.

Various modifications both in regard to the circuits as well as the physical embodiment of the devices may be employed without deviating from the spirit of my invention, and no undue limitation should therefore be deduced from the specific illustration given but the appended claims should be construed as broadly as possible in view of the prior art.

What I claim as new and desire to secure by Letters Patent is:

1. In a train control system, car carried equipment comprising a manually operable device having two extreme inactive and inoperative positions and a zone of intermediate brake-preventing positions, said device being normally maintained in one of its inactive of the brakes, a manual. device normally in inoperative position, said device when actuated assuming a brake-preventing position for a limited time only, after which it assumes a second inactive position which neither causes nor prevents :an application of the brakes.

3. In an automatic train control system, brake-controlling means normally inactive, and when activecausing an automatic appli cation of the brakes, and a manually operable mechanism having two inactive and inoperative extreme positions and an intermediate brake-preventing position, said manual device being normally in one of its inactive positions and when operated assuming a brakepreventing position for a limited time, after which it assumes the second inactive position.

4. In an automatic train control system, brake-controlling means, normally inactive but when active causing an automatic application of the brakes, a manually operable mechanism having inactive positions and a zone of brake-preventing positions, said manual device being normally in an inactive and inoperative position, and when operated passing. the brake-preventing zone, after which it reassumes a second inactive position.

5. In a train control system of the permissive type, a normally energized electro-responsive brake controlling device, brake-applying means normally inactive and rendered active upon de-energization of the electroresponsive device, a mechanism comprising two normally open contactors, an auxiliary circuit for re-energizing the electro-responsive device including said two normally open contactors, manual means to close one of said contactors and means to automatically close the other contactor upon actuation of the manual means, said automatically closed contactor re-opening after a predetermined time.

6. In a trainrcontrol system of the permissive type, an electro-responsive brake-controlling device normally energized, said electro-responsive device having a normal maintaining circuit and an auxiliary circuit, said auxiliary circuit serving to re-energizethe electro-responsive device after-its de-energization, a manually operable device comprising two rotatable contactors, both of said rotatable contactors being normally open and assuming a closed position upon operation of the device, to re-open after a predetermined time following operation, operation of said the normally open air-operated contact is closed, but not preventing a brake application and not permitting a release of the brakes if a speed controlled contactor is open.

8. In a system for automatic train control, the combination of train-carried brake-applying means and trackway devices transmitting an impulse to the train-carried means whenever danger conditions exist, two airoperated contacts, one normally close-d and the other normally open, it being possible to close only one of the two contacts at a time, a speed governor including a low speed and a high speed contact, an acknowledging device, said acknowledging device permitting, by identical manual operation of same, the prevention of automatic application of the brakes due to an impulse received from the I track provided the closed air-operated contact and the low speed contact of the speed governor are closed, and the release of an automatic brake application provided the open air-operated contact and the low speed contact of the speed governor are closed, said acknowledging device not preventing an automatic application of the brakes if the high speed contact of the speed governor is opened.

9. In a train control system, car carried equipment comprising an electro-responsive evice and an auxiliary energizing circuit for said device, a manually operable device comprising two contactors in series connection, said contactors forming part of the auxiliary circuit, an actuating member for said device having a normal and an operative position whereby in the normal position of the member both contactors are open and upon operation of said member one contactor is immediately closed and remains closed as long as said memb'eris held in the operative position, the other contactor being closed after a short interval of time and remaining closed for a longer interval and again rcopening thereafter, both contactors being openedimmediately when said member is returned to its normal position.

10. In a train control system, an electroresponsive device and an auxiliary circuit therefor, a forestalling device comprising a s ring biased shaft, an operating handle t erefor, and two rotatable contactors in series connection, said contactors forming part of the auxlllary c1rcu1t, one of said contactors being rigidly fixed to the shaft, the second contactor being loosely connected with the shaft by resilient means, a member connecting the two contactors and preventing the second contactor from rotating when the first contactor'is in its normal position, a clockwork mechanism to rotate the second con-' tactor, whereby manual rotation of the shaft by means of the handle causes rotation of the first contactor and the release of the second contactor, which is thereby rotated by the clockwork, said contactors normally assuming a position to open the auxiliary circuit and when rotated close this circuit for a limited time.

New York, N. Y., July 3d, 1929. s FRANK J. SPRAGUE. 

